Humans are living longer now than at any other point in history. However, if this trend is to continue we have to solve the physiological issues associated with aging. A recent study of an Amish community reveals that protecting ourselves from the negative effects of aging may be as simple as turning off a single gene.
It is easy to think of aging as a mysterious inevitability of life, but in reality, it is just the conjunction of several biological processes. Some of these processes are known, such as the progressive shortening of telomeres. Telomeres are the end-caps that prevent our DNA from unraveling as our cells replicate, but as we age they become shorter and less effective. What triggers these and other biological processes, however, has been largely unknown.
One potential trigger discovered is plasminogen activator inhibitor-1 (PAI-1). PAI-1 is a protein that becomes more present in our bodies as we get older. Previous studies have shown that this increase in PAI-1 is associated with cellular senescence or the aging and dying of our cells. This raised the question of whether or not an absence of PAI-1 would lead us to longer and healthier lives. Now, this new study conducted by Sadiya Khan and her research team at Northwestern University has shown that the answer may be yes.
The study took place in the Berne Amish community of Indiana where 177 individuals were tested for mutations in SERPINE1, the gene responsible for making PAI-1. Out of the 177 participants, 43 had mutations that resulted in a non-functioning null version of the SERPINE1 gene. The subjects of the study were then checked for some of the hallmarks signs of aging such as telomere length, fasting insulin level, and prevalence of type II diabetes
Remarkably, those with a null SERPINE1 gene had lower levels of PAI-1 and showed less significant signs of aging across every biological indicator. This result confirms that PAI-1 is indeed a factor in biological aging and that inactivating SERPINE1 can increase human longevity.
The authors of the paper recognize, however, that this study had several limitations. The Amish community studied is genetically isolated and has a recent common ancestor, meaning there could be many other genetic factors other than a null SERPINE1 that explain the results.
Furthermore, the entire Berne Amish community, with or without a functioning SERPINE1 mutation, was healthier on average than a randomly selected population. Therefore, the results may be specific to this community and a null SERPINE1 might not have similar effects elsewhere.
Finally, the participants in the study were all relatively young. Therefore those studied will have to be observed over many years to determine if there actually is increased longevity in those with a null SERPINE1.
Regardless, this study shows that we may be closer than ever to solving the mysteries of aging. Once the biological processes and triggers behind why we age are discovered, solutions and cures are sure to follow. In fact, Japan is already conducting early-stage human trials of pills that reduce the amount of PAI-1 in our bodies. Aging may soon be a thing of the past.